Transparent touch-responsive capacitor with variable-height micro-wires

ABSTRACT

A touch-responsive capacitive apparatus includes a transparent substrate having first and second pad and interstitial areas. Pairs of first and second pad areas define corresponding touch-responsive capacitors. Electrically connected first pad micro-wires are formed in the first pad areas and electrically connected first interstitial micro-wires are formed in the first interstitial areas. The first pad micro-wires are electrically connected to the first interstitial wires. Electrically connected second pad micro-wires are formed in the second pad areas and electrically connected second interstitial micro-wires are formed in the second interstitial areas. The second pad micro-wires are electrically connected to the second interstitial wires. The height of at least a portion of the first interstitial micro-wires is greater than the height of at least a portion of the first pad micro-wires.

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly-assigned, co-pending U.S. patentapplication Ser. No. ______ (Kodak Docket K000882), filed concurrentlyherewith, entitled “MAKING MICRO-WIRES WITH DIFFERENT HEIGHTS” by RonaldS. Cok, et al.; U.S. patent application Ser. No. ______ (Kodak DocketK000883), filed concurrently herewith, entitled “PATTERN-WISE DEFININGMICRO-WIRES WITH DIFFERENT HEIGHTS”, by Ronald S. Cok; U.S. patentapplication Ser. No. ______ (Kodak Docket K000884), filed concurrentlyherewith, entitled “ELECTRONIC DEVICE HAVING METALLIC MICRO-WIRES”, byRonald S. Cok, et al.; U.S. patent application Ser. No. ______ (KodakDocket K000885), filed concurrently herewith, entitled “TOUCH SCREENWITH DUMMY MICRO-WIRES”, by Ronald S. Cok, et al., and U.S. patentapplication Ser. No. ______ (Kodak Docket K000836), filed concurrentlyherewith, entitled “TRANSPARENT TOUCH-RESPONSIVE CAPACITOR WITHVARIABLE-PATTERN MICRO-WIRES”, by Ronald S. Cok, the disclosures ofwhich are incorporated herein.

FIELD OF THE INVENTION

The present invention relates to transparent conductors and their use incapacitive touch screens.

BACKGROUND OF THE INVENTION

Transparent conductors are widely used in the flat-panel displayindustry to form electrodes that are used to electrically switch thelight-emitting or light-transmitting properties of a display pixel, forexample in liquid crystal or organic light-emitting diode displays.Transparent conductive electrodes are also used in touch screens inconjunction with displays. In such applications, the transparency andconductivity of the transparent electrodes are important attributes. Ingeneral, it is desired that transparent conductors have a hightransparency (for example, greater than 90% in the visible spectrum) anda high conductivity (for example, less than 10 ohms/square).

Typical prior-art conductive electrode materials include indium tinoxide (ITO) and very thin layers of metal, for example silver oraluminum or metal alloys including silver or aluminum. These materialsare coated, for example, by costly vacuum deposition methods such assputtering or vapor deposition, and patterned on display or touch screensubstrates, such as glass. Patterning is typically done by traditionalmulti-step lithographic processes. However, the current-carryingcapacity of such electrodes is limited, thereby limiting the amount ofpower that can be supplied to the pixel elements. Moreover, thesubstrate materials are limited by the deposition process (e.g.sputtering). Thicker layers of metal oxides or metals increaseconductivity but reduce the transparency of the electrodes.

Various methods of improving the conductivity of transparent conductorsare taught in the prior art. For example, issued U.S. Pat. No. 6,812,637entitled “OLED Display with Auxiliary Electrode” by Cok, describes anauxiliary electrode to improve the conductivity of the transparentelectrode and enhance the current distribution. Such auxiliaryelectrodes are typically provided in areas that do not block lightemission, e.g., as part of a black-matrix structure.

It is also known in the prior art to form conductive traces usingnano-particles comprising, for example silver. The synthesis of suchmetallic nano-crystals is known. For example, issued U.S. Pat. No.6,645,444 entitled “Metal nano-crystals and synthesis thereof” describesa process for forming metal nano-crystals optionally doped or alloyedwith other metals. U.S. Patent Application Publication No. 2006/0057502entitled “Method of forming a conductive wiring pattern by laserirradiation and a conductive wiring pattern” describes fine wirings madeby drying a coated metal dispersion colloid into a metal-suspension filmon a substrate, pattern-wise irradiating the metal-suspension film witha laser beam to aggregate metal nano-particles into larger conductivegrains, removing non-irradiated metal nano-particles, and formingmetallic wiring patterns from the conductive grains. However, such wiresare not transparent and thus the number and size of the wires limits thesubstrate transparency as the overall conductivity of the wiresincreases.

Touch screens with transparent electrodes are widely used withelectronic displays, especially for mobile electronic devices. Suchdevices typically include a touch screen mounted over an electronicdisplay that displays interactive information. Touch screens mountedover a display device are largely transparent so that a user can viewdisplayed information through the touch screen and readily locate apoint on the touch screen to touch and thereby indicate the informationrelevant to the touch. By physically touching, or nearly touching, thetouch screen in a location associated with particular information, auser can indicate an interest, selection, or desired manipulation of theassociated particular information. The touch screen detects the touchand then electronically interacts with a processor to indicate the touchand touch location. The processor can then associate the touch and touchlocation with displayed information to execute a programmed taskassociated with the information. For example, graphic elements in acomputer-driven graphic user interface are selected or manipulated witha touch screen mounted on a display that displays the graphic userinterface.

Touch screens use a variety of technologies, including resistive,inductive, capacitive, acoustic, piezoelectric, and opticaltechnologies. Such technologies and their application in combinationwith displays to provide interactive control of a processor and softwareprogram are well known in the art. Capacitive touch screens are of atleast two different types: self-capacitive and mutual capacitive.Self-capacitive touch screens can employ an array of transparentelectrodes, each of which in combination with a touching device (e.g. afinger or conductive stylus) forms a temporary capacitor whosecapacitance can be detected. Mutual-capacitive touch screens can employan array of transparent electrode pairs that form capacitors whosecapacitance is affected by a conductive touching device. In either case,each capacitor in the array can be tested to detect a touch and thephysical location of the touch-detecting electrode in the touch screencorresponds to the location of the touch. For example, U.S. Pat. No.7,663,607 discloses a multipoint touch screen having a transparentcapacitive sensing medium configured to detect multiple touches or neartouches that occur at the same time and at distinct locations in theplane of the touch panel and to produce distinct signals representativeof the location of the touches on the plane of the touch panel for eachof the multiple touches. The disclosure teaches both self- andmutual-capacitance touch screens.

Referring to FIG. 10, a prior-art touch screen and display system 100includes a display 110 with a corresponding touch screen 120 mountedwith the display 110 so that information displayed on the display 110 isviewed through the touch screen 120. Graphic elements displayed on thedisplay 110 can be selected, indicated, or manipulated by touching acorresponding location on the touch screen 120. The touch screen 120includes a first transparent substrate 122 with first transparentelectrodes 130 formed in the x-dimension on the first transparentsubstrate 122 and a second transparent substrate 126 with secondelectrodes 132 formed in the y-dimension facing the x-dimension firsttransparent electrodes 130 on the second transparent substrate 126. Adielectric layer 124 is located between the first and second transparentsubstrate 122, 126 and first and second transparent electrodes 130, 132.Referring also to the top view of FIG. 11, in this example first padareas 128 in the first transparent electrodes 130 are located adjacentto second pad areas 129 in the second transparent electrodes 132. (Thefirst and second pad areas 128, 129 are separated into differentparallel planes by the dielectric layer 124.) The first and secondtransparent electrodes 130, 132 have a variable width and extend inorthogonal directions (for example as shown in U.S. Patent PublicationNos. 2011/0289771 and 2011/0099805, which are hereby incorporated byreference. When a voltage is applied across the first and secondtransparent electrodes 130, 132, electric fields are formed between thefirst pad areas 128 of the x-dimension first transparent electrodes 130and the second pad areas 129 of the y-dimension second electrodes 132.

Another prior-art disclosure of a touch screen with variable-widthelectrodes and sensing cells is found in U.S. Patent Publication No.2011/0248953. Conductive dummy patterns are located between adjacentsensing cells at different heights above a transparent substrate and theconductive dummy patterns partially overlap the sensing cells.

A display controller 142 controls the display 110 in coordination with atouch screen controller 140. The touch screen controller 140 isconnected through electrical buss connections 136, 134 and controls thetouch screen 120. The touch screen controller 140 detects touches on thetouch screen 120 by sequentially electrically energizing and testing thex-dimension first and y-dimension second transparent electrodes 130,132.

Referring to FIG. 12, in another prior-art embodiment, rectangular firstand second transparent electrodes 130, 132 are arranged orthogonally onfirst transparent substrate 122, 126 with intervening dielectric layer124, forming touch screen 120 which, in combination with the display 110forms a touch screen and display system 100. First and second pad areas128, 129 are formed where the first and second transparent electrodes130, 132 overlap. The touch screen 120 and display 110 are controlled bytouch screen and display controllers 140, 142 respectively, throughelectrical busses 136 and 134.

Since touch screens are largely transparent, any electrically conductivematerials located in the transparent portion of the touch screen eitheremploy transparent conductive materials (for example, transparentconductive metal oxides such as indium tin oxide) or employ conductiveelements that are too small to be readily resolved by the eye of a touchscreen user. Transparent conductive metal oxides are well known in thedisplay and touch screen industry and have a number of disadvantages,including inadequate transparency and conductivity, high manufacturingcosts due to vacuum processes and a tendency to crack under mechanicalor environmental stress. Further, the high demand for indium hassignificantly increased the price of this raw material. Thus, touchscreens including very fine patterns of conductive elements, such asmetal wires or conductive traces can provide a useful alternative. Forexample, U.S. Patent Publication No. 2011/0007011 teaches a capacitivetouch screen with a mesh electrode, as does U.S. Patent Publication No.2010/0026664.

Referring to FIG. 13, a prior-art x- or y-dimension variable-widthtransparent electrode 130, 132 includes a micro-pattern 156 ofmicro-wires 150 arranged in a rectangular grid. The micro-wires 150 aremultiple very thin metal conductive traces or wires formed on the firstand second transparent substrates 122, 126 to form the x- andy-dimension transparent electrodes 130, 132. The micro-wires 150 are sothin that they are not readily visible to a human observer, for example1 to 10 microns wide. The micro-wires 150 are typically opaque andspaced apart, for example by 50 to 500 microns, so that the first andsecond transparent electrodes 130, 132 appear to be transparent and themicro-wires 150 are not distinguished by an observer.

U.S. Patent Publication No. 2009/0219257 discloses a touch screen sensorthat includes a visible light transparent substrate and an electricallyconductive micro-pattern disposed on or in the visible light transparentsubstrate. The micro-pattern includes a first region micro-pattern witha first sheet resistance value and a second region micro-pattern with asecond sheet resistance different from the first sheet resistance value.As disclosed, the second region sheet resistance is lower than the firstand includes micro-breaks in the conductive micro-pattern.

Mutually-capacitive touch screens typically include arrays of capacitorswhose capacitance is repeatedly tested to detect a touch. In order todetect touches rapidly, highly conductive electrodes are useful. Inorder to readily view displayed information on a display at a displaylocation through a touch screen, it is useful to have a highlytransparent touch screen. There is a need, therefore, for an improvedmethod and apparatus for providing electrodes with increasedconductivity and transparency in a mutually capacitive touch screendevice.

SUMMARY OF THE INVENTION

In accordance with the present invention, a touch-responsive capacitiveapparatus comprises:

a transparent substrate;

a plurality of electrically connected first pad micro-wires formed in aplurality of first pad areas in a first micro-wire layer and a pluralityof electrically connected first interstitial micro-wires formed in aplurality of first interstitial areas in the first micro-wire layer, thefirst pad micro-wires electrically connected to the first interstitialwires;

a plurality of electrically connected second pad micro-wires formed in aplurality of second pad areas in a second micro-wire layer and aplurality of electrically connected second interstitial micro-wiresformed in a plurality of second interstitial areas in the secondmicro-wire layer, the second pad micro-wires electrically connected tothe second interstitial wires; and

wherein pairs of first and second pad areas define correspondingtouch-responsive capacitors, the transparent substrate supports thefirst or second micro-wire layers, and the height of at least a portionof the first interstitial micro-wires is greater than the height of atleast a portion of the first pad micro-wires.

The present invention provides improved conductivity and performance fortransparent micro-wire electrodes in electronic devices and mutuallycapacitive touch screens without deleteriously affecting thetransparency or function of the apparatus.

These, and other, attributes of the present invention will be betterappreciated and understood when considered in conjunction with thefollowing description and the accompanying drawings. It should beunderstood, however, that the following description, although indicatingembodiments of the present invention and numerous specific detailsthereof, is given by way of illustration and not of limitation. Forexample, the summary descriptions above are not meant to describeindividual separate embodiments whose elements are not interchangeable.Many of the elements described as related to a particular embodiment canbe used together with, and interchanged with, elements of otherdescribed embodiments. The figures below are not intended to be drawn toany precise scale with respect to relative size, angular relationship,or relative position or to any combinational relationship with respectto interchangeability, substitution, or representation of an actualimplementation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent when taken in conjunction with the followingdescription and drawings wherein identical reference numerals have beenused to designate identical features that are common to the figures, andwherein:

FIGS. 1A and 1B are exploded perspectives illustrating an embodiment ofthe present invention;

FIGS. 2A and 2B are top-view schematics illustrating an embodiment ofthe present invention;

FIG. 3 is an exploded perspective illustrating an embodiment of thepresent invention;

FIGS. 4A and 4B are cross-sections illustrating embodiments of thepresent invention;

FIGS. 5A-5C are flow diagrams illustrating various methods of variousembodiments of the present invention;

FIGS. 6A-6B are flow diagrams illustrating various methods of variousembodiments of the present invention;

FIGS. 7A-7B are flow diagrams illustrating various methods of variousembodiments of the present invention;

FIG. 8 is a schematic cross section of a two-layer structure useful inunderstanding a method of the present invention;

FIG. 9 is a schematic cross section of a printing plate useful inunderstanding a method of the present invention;

FIG. 10 is a prior-art exploded perspective illustrating a mutualcapacitive touch screen having adjacent pad areas in conjunction with adisplay and controllers;

FIG. 11 is a prior-art schematic illustrating pad areas in a capacitivetouch screen;

FIG. 12 is a prior-art exploded perspective illustrating a mutualcapacitive touch screen having overlapping pad areas in conjunction witha display and controllers;

FIG. 13 is a prior-art schematic illustrating micro-wires in anapparently transparent electrode;

FIG. 14 is a top-view schematic of an electronic device havingtransparent conductor areas according to an embodiment of the presentinvention;

FIG. 15 is a cross-section schematic of an electronic device havingtransparent conductor areas according to an embodiment of the presentinvention;

FIG. 16 is a cross-section schematic of an electronic device havingmultiple layers according to an embodiment of the present invention.

FIG. 17 is a top-view schematic of a transparent conductor apparatushaving dummy areas in an embodiment of the present invention;

FIG. 18 is a top-view detail schematic of a transparent conductorapparatus having dummy areas in an embodiment of the present invention;

FIGS. 19A, 19B, and 19C are top-view schematics illustrating dummy areasand dummy micro-wires useful in understanding various embodiments of thepresent invention; and

FIGS. 20A and 20B are cross-sections illustrating the relative heightsof interstitial wires, pad micro-wires, and dummy micro-wires useful inunderstanding various embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1A and 1B, according to an embodiment of the presentinvention, a touch-responsive capacitive apparatus 10 includes a firsttransparent substrate 122. A plurality of first pad areas 128 and firstinterstitial areas 12 are formed in a first micro-wire layer and aplurality of second pad areas 129 and second interstitial areas 14 areformed in a second micro-wire layer. Pairs of first and second pad areas128, 129 define corresponding touch-responsive capacitors. The first orsecond micro-wire layers are supported by the first transparentsubstrate 122. Thus, the first or second pad areas 128, 129 and first orsecond interstitial areas 12, 14 can be formed upon one or the othersides of the first transparent substrate 122 or on layers located upon,over, under, or adjacent to one or the other sides of the firsttransparent substrate 122. As illustrated in the example of FIGS. 1A and1B, the first pad areas 128 and first interstitial areas 12 are formedover the first transparent substrate 122 while the second pad areas 129and second interstitial areas 14 are formed on a second transparentsubstrate 126 located over the first transparent substrate 122. Thefirst and second transparent substrates 122, 126 are separated by adielectric layer 124.

As shown in FIG. 1A and referring further to the top view of FIG. 2A,the first pad areas 128 are adjacent to the second pad areas 129 and thefirst interstitial areas 12 overlap the second interstitial areas 14. Asshown in FIG. 1B and referring further to FIG. 2B, the first pad areas128 overlap the second pad areas 129 and the first interstitial areas 12are adjacent to the second interstitial areas 14. In this embodiment,dummy areas 160 between pad and interstitial areas 128, 129, 12, 14 haveno electrical functionality.

Referring to FIG. 3 and corresponding to the example of FIG. 2B,micro-wires 150 form first and second transparent electrodes 130, 132 inthe first and second micro-wire layers, respectively. A plurality ofelectrically connected pad micro-wires 24 are formed in the first padareas 128 in the first micro-wire layer and a plurality of electricallyconnected interstitial micro-wires 22 are formed in the firstinterstitial areas 12 in the first micro-wire layer. The pad micro-wires24 are electrically connected to the interstitial micro-wires 22 in thefirst micro-wire layer. Likewise, a plurality of electrically connectedpad micro-wires 24 are formed in the second pad areas 129 in the secondmicro-wire layer and a plurality of electrically connected interstitialmicro-wires 22 are formed in the second interstitial areas 14 in thesecond micro-wire layer. The pad micro-wires 24 are electricallyconnected to the interstitial micro-wires 22 in the second micro-wirelayer. The height of at least a portion of the interstitial micro-wires22 is greater than the height of at least a portion of the padmicro-wires 24. The interstitial or pad micro-wires form a micro-patternof micro-wires. The interstitial and pad micro-wires 22, 24 can form thesame or different micro-patterns of micro-wires 150.

First transparent electrodes 130 extending in the x-dimension are formedon the first transparent substrate 122. Second transparent electrodes132 extending in the y-dimension are formed on the second transparentsubstrate 126. The second transparent substrate 126 is located above thefirst transparent substrate 122 and a dielectric layer 124 is locatedbetween the first and second transparent substrates 122, 126. The firstpad areas 128 and the first interstitial areas 12 are spaced apart anddo not overlap but can be contiguous. Likewise, the second pad areas 129and the second interstitial areas 14 are spaced apart and do not overlapbut can be contiguous. Touch-responsive capacitors are formed by theelectric fields resulting from electrical charges placed on the padmicro-wires 24 in the first and second pad areas 128, 129 of the firstand second transparent electrode 130, 132 separated by dielectric layer124.

FIGS. 1A and 1B illustrate a first transparent substrate 122 on whichthe first transparent electrodes 130 are formed and a separate secondtransparent substrate 126 on which the second transparent electrodes 132are formed above the first transparent substrate 122. However, otherembodiments will suggest themselves to those skilled in the art. In theembodiment illustrated in FIGS. 1A, 1B, 3 and 4A, first transparentelectrodes 130 are formed above a first transparent substrate 122 andsecond transparent electrodes 132 are formed beneath a separate secondtransparent substrate 126 located above the first transparent substrate126 so that the first and second transparent electrodes 130, 132 areseparated only by the dielectric layer 124 (not shown in FIGS. 2A, 2B,and 3). First transparent electrodes 130 include short pad micro-wires24 having a height H2 in first pad areas 128 and tall interstitialmicro-wires 22 having a height H1 greater than H2 in first interstitialareas 12. Second transparent electrodes 132 include short padmicro-wires 24 in second pad areas 129 having a height H2 and tallinterstitial micro-wires 22 in second interstitial areas 14 having aheight H1 greater than H2. As used herein, the height of a micro-wire150 is the actual thickness (or depth) of the micro-wire 150 from thebottom surface of the micro-wire 150 to the opposed, top surface. Thebottom surface can be considered the surface closest to the substrate(e.g. first or second transparent substrates 122, 126) on, over, orunder which the micro-wire 150 is formed. The height of a micro-wire 150is an attribute of the micro-wire 150 and does not refer to itslocation, for example the height of a micro-wire 150 does not refer toits general location above or below a substrate on, over, or under whichit is located.

In an alternative embodiment of the present invention illustrated inFIG. 4B and discussed further below, a transparent substrate 123 havingfirst transparent electrodes 130 including interstitial and padmicro-wires 22, 24 are located above one side of the transparentsubstrate 123 and second transparent electrodes 132 includinginterstitial and pad micro-wires 22, 24 are located below an opposingside of the transparent substrate 123 and the transparent substrate 123is the dielectric layer 124. Again, first transparent electrodes 130include short pad micro-wires 24 having a height 112 having a height H1greater than H2 in first pad areas 128 and tall interstitial micro-wires22 in first interstitial areas 12. Second transparent electrodes 132include short pad micro-wires 24 in second pad areas 129 having a heightH2 and tall interstitial micro-wires 22 in second interstitial areas 14having a height H1 greater than H2.

The micro-wires 24 in the first pad areas 128 and second pad areas 129form electric fields when energized with a charge.

The first transparent electrodes 130 have two different types of areas,first pad areas 128 and first interstitial areas 12. The first pad areas128 and the first interstitial areas 12 of the first transparentelectrode 130 are formed in a first micro-wire plane. Similarly, thesecond transparent electrodes 132 have two different types of areas,second pad areas 129 and second interstitial areas 14 (not shown inFIGS. 4A and 4B). The second pad areas 129 and the second interstitialareas 14 of the second transparent electrode 132 are formed in a secondmicro-wire plane different from the first micro-wire plane in which thefirst transparent electrode 130 is formed.

The first and second transparent electrodes 130, 132 are made up ofmicro-wires 150 in both the first and second pad areas 128, 129 and thefirst and second interstitial areas 12, 14 respectively. Micro-wires arerelatively small conductive traces compared to the first pad areas 128,second pad areas 129, first interstitial areas 12, or secondinterstitial areas 14 so that the majority of the area over the firsttransparent substrate 122 (or second transparent substrate 126 ortransparent substrate 123) is transparent and does not includemicro-wires 150, as illustrated in prior art FIG. 13. In FIG. 13, themajority of the area in the first and second transparent electrodes 130,132 is open space. Micro-wires can be metal, for example silver, gold,aluminum, nickel, tungsten, titanium, tin, or copper or various metalalloys including, for example silver, gold, aluminum, nickel, tungsten,titanium, tin, or copper. Alternatively, the first or second micro-wires152, 154 (shown on FIGS. 3, 14-16, 18) can include cured or sinteredmetal particles such as nickel, tungsten, silver, gold, titanium, or tinor alloys such as nickel, tungsten, silver, gold, titanium, or tin.Other materials or methods for forming micro-wires 150 can be employedand are included in the present invention.

As used herein, micro-wires 150 in each electrode are micro-wires 150formed in a micro-wire layer that forms a conductive mesh ofelectrically connected micro-wires 150. Thus, the pad micro-wires 24 inthe first pad areas 128 are in the same micro-wire layer as theinterstitial micro-wires 22 in the first interstitial areas 12.Similarly, the pad micro-wires 24 in the second pad areas 129 are in thesame micro-wire layer as the interstitial micro-wires 22 in the secondinterstitial areas 14. A micro-wire layer is a layer in which there isno intervening layer between pad micro-wires 24 and interstitialmicro-wires 22 on the same substrate side. Thus, the pad micro-wires 24in the first pad areas 128 of the first transparent electrode 130 are ina first layer with the interstitial micro-wires 22 in the firstinterstitial areas 12 of the first transparent electrode 130. Similarly,the pad micro-wires 24 in the second pad areas 129 of the secondtransparent electrode 132 are in a second different micro-wire layerwith the interstitial micro-wires 22 in the second interstitial areas 14of the second transparent electrode 132. In particular, a micro-wire 150that passes over another micro-wire 150 is no longer in the samemicro-wire layer as the other micro-wire 150. Also, a micro-wire 150that is electrically connected to another micro-wire 150 through a viais no longer in the same micro-wire layer as the other micro-wire 150.If a transparent substrate is planar, for example, a rigid planarsubstrate such as a glass substrate, the micro-wires 150 in a layer aresimilarly formed in, or on, a common plane. If a transparent substrateis flexible and curved, for example, a plastic substrate, themicro-wires 150 in a micro-wire layer are a conductive electricallyconnected mesh that is a common distance from a surface of the plasticsubstrate.

The micro-wires 150 can be formed on a transparent substrate 123 or on alayer above (or beneath) the transparent substrate 123. The pad andinterstitial micro-wires 24, 22 for each of the first and secondtransparent electrodes 130, 132 can be formed on opposing sides of thesame transparent substrate 123 (e.g. as shown in FIG. 4B) or on facingsides of separate transparent substrates 122, 126 (e.g. as shown in FIG.4A). Although some of the micro-wires 150 (e.g. 22) in a transparentelectrode (e.g. 130) are taller than other of the micro-wires 150 (e.g.24) in the transparent electrode (e.g. 130), they are considered to bein the same common plane because continuous portions of the micro-wires150 are at a common distance from the transparent substrate.

The pad micro-wires 24 in the first pad areas 128 or the interstitialmicro-wires 22 in the first interstitial areas 12 of a first transparentelectrode 130 are electrically interconnected within the first pad areas128 and within the first interstitial areas 12. Likewise, the padmicro-wires 24 in the second pad areas 129 or the interstitialmicro-wires 22 in the second interstitial areas 14 of a secondtransparent electrode 132 are electrically interconnected within thesecond pad areas 129 and within the second interstitial areas 14. Theinterstitial or pad micro-wires 22, 24 of the first transparentelectrode 130 are not electrically connected to the interstitial or padmicro-wires 22, 24 of the second transparent electrode 132, as such anelectrical connection would cause an electrical short across thetouch-responsive capacitors.

The height of the interstitial micro-wires 22 in the first interstitialareas 12 of the first transparent electrode 130 is greater than theheight of the pad micro-wires 24 in the first pad areas 128 of the firsttransparent electrode 130. Likewise, the height of the interstitialmicro-wires 22 in the second interstitial areas 14 of the secondtransparent electrode 132 is greater than the height of the padmicro-wires 24 in the second pad areas 129 of the second transparentelectrode 132. The height of a micro-wire 150 is the vertical thicknessof the micro-wire 150 on the transparent substrate (e.g. 123) surfaceand is distinguished from the width or length of the micro-wire 150across the extent of the transparent substrate (e.g. 123) on, above, orbelow which it is formed. It does not refer to, for example, thevertical distance from the substrate or separation between substrates orsubstrate layers. Thus, the conductivity of the interstitial micro-wires22 in the first interstitial areas 12 is greater than the conductivityof the pad micro-wires 24 in the first pad areas 128 of the firsttransparent electrode 130 because it is thicker and has a greater wirecross section. Likewise, the conductivity of the interstitialmicro-wires 22 in the second interstitial areas 14 is greater than theconductivity of the pad micro-wires 24 in the second pad areas 129 ofthe second transparent electrode 132 because it is thicker and has agreater wire cross section. Hence, according to embodiments of thepresent invention, the overall conductivity of the first and secondtransparent electrodes 130, 132 are increased and the resistivityreduced.

Since, in a capacitor array formed by overlapping or adjacent orthogonaltransparent electrodes (e.g. 130, 132) each capacitor is electricallytested to determine its capacitance and to detect a touch, the RC timeconstant of the circuit formed by each pair of electrodes limits therate at which the capacitors can be tested. The RC time constant can bereduced by increasing the conductivity and reducing the resistance (R)of the electrodes. By increasing electrode conductivity and thereforethe rate at which the capacitors are tested, faster performance andbetter user response is provided. Alternatively or in addition, anincrease in the number of capacitors is enabled, providing increasedresolution in a capacitor array. Hence, the present invention canprovide improved and faster performance and increased resolution oftouch screen capacitor arrays.

In another embodiment of the present invention, the width of theinterstitial micro-wires 22 in the first interstitial area 12 is thesame as the width of the pad micro-wires 24 in the first pad area 128.

The exploded perspectives of FIGS. 1A and 1B illustrate firsttransparent electrodes 130 formed on a first transparent substrate 122facing orthogonal second transparent electrodes 132 on a secondtransparent substrate 126. First interstitial areas 12 on the firsttransparent substrate 122 are shown taller than the first pad areas 128of the first transparent electrode 130 to indicate that the interstitialmicro-wires 22 (not shown) making up the conductive elements of thefirst transparent electrode 130 in the first interstitial areas 12 aretaller than the pad micro-wires 24 (not shown) making up the conductiveelements of the first transparent electrode 130 in the first pad areas128. Similarly, second interstitial areas 14 on the second transparentsubstrate 126 are shown taller than the second pad areas 129 of thesecond transparent electrode 132 to indicate that the interstitialmicro-wires 22 (not shown) making up the conductive elements of thesecond transparent electrode 132 in the second interstitial areas 14 aretaller than the pad micro-wires 24 making up the conductive elements ofthe second transparent electrode 132 in the second pad areas 129.Micro-wires 150 are not shown in FIG. 1A or 1B.

The top view of the touch-responsive capacitor apparatus 10 in FIGS. 2Aand 2B illustrate the first and second orthogonal transparent electrodes130, 132. In FIG. 2B, some of the first and second pad areas 128, 129are indicated with heavy dashed rectangles. Some of the first and secondinterstitial areas 12, 14 are similarly indicated with heavy dashedrectangles. There are some areas in which there are no electrodes;electrically disconnected micro-wires 150 (not shown) can be located insuch areas to maintain optical similarity over the surface of thetransparent substrates e.g. 122, 126 (not shown).

The exploded perspective of the touch-responsive capacitor apparatus 10in FIG. 3 illustrates first transparent electrodes 130 formed on a firsttransparent substrate 122 facing orthogonal second transparentelectrodes 132 on a second transparent substrate 126. The first andsecond orthogonal transparent electrodes 130, 132 are each shown withparallel and orthogonal micro-wires 150 forming a grid micro-pattern 156in each first and second electrode 130, 132. (For clarity, only a fewmicro-wires 150 for each first and second transparent electrode 130, 132are illustrated. In actual practice, many micro-wires 150 would be usedto extend to the edges of the first and second transparent electrodes130, 132.) The pad micro-wires 24 in the first and second pad areas 128,129 are shown shorter than the interstitial micro-wires 22 in the firstor second interstitial areas 12, 14. The micro-pattern 156 defines therelative locations and orientations of the micro-wires 150 and isindependent of the transparent electrode pattern, although both can berectangular arrays. In other embodiments, the micro-pattern is differentfrom the electrode pattern or is at a different orientation from theelectrode pattern. For example, as illustrated in FIG. 13, themicro-pattern forms a regular grid array while the electrode patternforms a variable width diamond structure.

As illustrated in FIGS. 1A, 1B, 2A, 2B, and 3, each first transparentelectrode 130 includes multiple first pad areas 128 and multiple firstinterstitial areas 12. The pad and interstitial micro-wires 24, 22 ofthe multiple first pad areas 128 and multiple first interstitial areas12, are electrically connected. Each first interstitial area 12electrically connects one or more first pad areas 128. In an embodiment,the first interstitial areas 12 are interspersed between first pad areas128 so that each first transparent electrode 130 includes alternatingfirst pad areas 128 separated by alternating first interstitial areas 12(except at the ends of the first electrodes). Likewise, the secondinterstitial areas 14 are interspersed between second pad areas 129 sothat each second transparent electrode 132 includes alternating secondpad areas 129 separated by alternating second interstitial areas 14(except at the ends of the second electrode). The first and secondtransparent electrodes 130, 132 can be orthogonal or extend in differentfirst and second directions over a transparent substrate (e.g. 122, 123,126). In the embodiment of FIG. 2A, gaps between the first transparentelectrodes 130 form the second interstitial areas 14 in the secondtransparent electrode 132 while the gaps between the second transparentelectrodes 132 can form the first interstitial areas 12 in the firsttransparent electrodes 130. In the embodiment of FIG. 2B, gaps betweenthe first transparent electrodes 130 form the second interstitial areas14 in the second transparent electrode 132 while the gaps between thesecond transparent electrodes 132 can form the first interstitial areas12 in the first transparent electrodes 130.

In an example and non-limiting embodiment of the present invention, eachmicro-wire is 5 microns wide and separated from neighboring parallelmicro-wires 150 in an electrode by a distance of 50 microns, so that theelectrode is 90% transparent. As used herein, transparent refers toelements that transmit at least 50% of incident visible light. Themicro-wires 150 can be arranged in a grid micro-pattern (as illustratedin FIGS. 3 and 11) that is unrelated to the pattern of the electrodes.Other micro-patterns are also used in other embodiments and the presentinvention is not limited by the micro-pattern of the micro-wires 150 orthe pattern of the first and second transparent electrodes 130, 132.Each first or second transparent electrode 130, 132 can be 1,000 micronswide (and thus include 20 micro-wires 150 across its width) andseparated from neighboring first or second transparent electrodes 130,132 by a distance of 333.3 microns. Therefore, each first pad area 128is 1,000 microns by 1,000 microns, each first interstitial area 12 is333.3 microns by 1,000 microns and each second interstitial area 14 is1,000 microns by 333.3 microns. If the electrodes on each first andsecond transparent substrate 122, 126 are aligned, this results in afirst and second transparent substrate 122, 126 with a transparency of{(90%×9)+(90%×6)+(100%×1)}/16 corresponding to the transparency of thefirst or second pad area 128, 129, the first or second interstitial area12, 14, and the area with no electrodes and equal to 90.6%.

Presuming that each interstitial micro-wire 22 in the first or secondinterstitial areas 12, 14 is twice the height (and half the resistance)of the pad micro-wires 24 in the first or second pad areas 128, 129 ofthe corresponding first and second transparent electrodes 130, 132, thenthe conductivity of the first and second transparent electrodes 130, 132is ({(3×1)+(1×0.5)}/4 or 0.875 for a reduction of 12.5% in resistanceand a corresponding reduction in the RC time constant. The capacitanceof the capacitors is unchanged.

Referring again to FIGS. 1A, 1B, and 3, in a further embodiment of thepresent invention, a transparent conductor apparatus 11 includes a firsttransparent substrate 122 having a first area 12 (e.g. interstitial area12) and a second area 128 (e.g. pad area 128) different from the firstinterstitial area 12. A plurality of electrically connected firstmicro-wires 152 is formed on the first transparent substrate 122 in afirst layer in the first area 12. A plurality of electrically connectedsecond micro-wires 154 is formed on the first transparent substrate 122in the first layer in the second area 128 and the electrically connectedsecond micro-wires 154 are electrically connected to the firstmicro-wires 152. The height of at least a portion of the firstmicro-wires 152 in the first area 12 is greater than the height of atleast a portion of the second micro-wires 154 in the second area 128.

FIG. 4A is a cross section of the structures shown in FIGS. 1A, 1B, and3 corresponding to the cross section line A of FIG. 2B. In thisembodiment of the present invention, a touch-responsive capacitorapparatus 10 includes a first transparent substrate 122 on which isformed first transparent electrodes 130 and a second transparentsubstrate 126 on which is formed second transparent electrodes 132orthogonal to the first transparent electrodes 130. The first and secondtransparent electrodes 130, 132 both include relatively tallinterstitial micro-wires 22 and relatively short pad micro-wires 24. Thefirst and second transparent electrodes 130, 132 face each other fromopposite sides of a dielectric layer 124. A plurality of spaced-apartfirst and second pad areas 128 and 129 whose capacitance changes inresponse to a touch is formed where the first and second transparentelectrodes 130, 132 are adjacent or overlap. A plurality of spaced-apartfirst interstitial areas 12 is formed on the first transparent substrate122 in the first transparent electrode 130. A plurality of spaced-apartsecond interstitial areas 14 is formed on the second transparentsubstrate 126 in the second transparent electrode 132 spaced apart fromthe second pad areas 129. The second interstitial areas 14 are not shownin FIG. 4A since they are located out of the plane on which FIG. 4A isdrawn. See the top view of FIG. 2 or the perspective of FIG. 1.

Referring to FIG. 4B in an alternative embodiment of the presentinvention, a touch-responsive capacitor apparatus 10 includes atransparent substrate 123 having first and second sides 123A, 123B,respectively. A first transparent electrode 130 is formed on or over thefirst side 123A of the transparent substrate 123 and includes relativelyshort pad micro-wires 24 and relatively tall interstitial micro-wires 22formed in a first layer. A second orthogonal transparent electrode 132is formed on or under the second side 123B of the transparent substrate123 and also includes relatively short pad micro-wires 24 and relativelytall interstitial micro-wires 22 formed in a second layer different fromthe first layer. In this embodiment, transparent substrate 123 alsoserves the function of dielectric layer 124. A plurality of spaced-apartfirst and second pad areas 128, 129 pairs is formed that definecapacitors whose capacitance changes in response to a touch. (In FIGS.4A and 4B, the first pad areas 128 are at a different depth from thesecond pad areas 129 and are not separately illustrated.) A plurality ofspaced-apart first interstitial areas 12 is formed over the first side123A of the transparent substrate 123 and spaced apart from the firstpad areas 128. A plurality of spaced-apart second interstitial areas 14is formed under the second side 123B of the transparent substrate 123and spaced apart from the second pad areas 129 and from the firstinterstitial areas 12 (in an orthogonal dimension). The secondinterstitial areas 14 are not indicated in FIG. 4B since they arelocated out of the plane on which FIG. 4B is drawn. See the top view ofFIG. 2 or the perspective of FIG. 1.

A first plurality of interstitial micro-wires 22 are formed over thefirst side 123A of the dielectric substrate layer 124 in a first layerin the first interstitial areas 12. A first plurality of pad micro-wires24 is formed over the first side 123A of the transparent substrate 123in the first layer in the first pad areas 128 and the pad micro-wires 24are electrically connected to the interstitial micro-wires 22. A secondplurality of interstitial micro-wires 22 are formed under the secondside 123B of the transparent substrate 123 in the second interstitialareas 14 in a second layer different from the first layer. A secondplurality of pad micro-wires 24 are formed on or under the second side123B of the transparent substrate 123 in the second layer in the firstpad areas 128 and are electrically connected to the second plurality ofinterstitial micro-wires 22. (The pad and interstitial micro-wires 24,22 and the second interstitial areas 14 are not indicated in FIG. 4A or4B but are shown in FIG. 3.) A dielectric layer 124 is located betweenthe first and second pluralities of micro-wires 150. In an embodiment,the dielectric layer 124 provides the transparent substrate 123.Alternatively, the dielectric layer 124 is a layer separate from thetransparent substrate 123. The height of at least a portion of theinterstitial micro-wires 22 in the first interstitial area 12 is greaterthan the height of at least a portion of the pad micro-wires 24 in thefirst pad area 128 over the first side 123A and the height of at least aportion of the interstitial micro-wire 22 in the second interstitialarea 14 is greater than the height of at least a portion of the padmicro-wires 24 in the first pad area 128 under the second side 123B.

In a further embodiment of the present invention, pad and interstitialmicro-wires 24, 22 forming first or second transparent electrodes 130,132 having first or second pad areas 128, 129 and first or secondinterstitial areas 12, 14 are located on either side of a dielectriclayer 124. Thus, the dielectric layer 124 has a first side 123A and asecond side 123B opposite the first side. The first side 123A isadjacent the first layer and the second layer is formed under the secondside 123B of the dielectric layer 124.

In a further embodiment of the present invention and as illustrated inFIGS. 1A, 1B, 2A, 2B, and 3, a first plurality of the interstitial andpad micro-wires 22, 24 form an array of first separated transparentelectrodes 130 arranged in a first direction and a second plurality ofthe interstitial and pad micro-wires 22, 24 form an array of secondseparated transparent electrodes 132 arranged in a second directiondifferent from the first direction, for example an orthogonal direction.The first transparent electrodes 130 can overlap or be adjacent to thesecond transparent electrodes 132 in the first or second pad areas 128,129. Likewise, the first transparent electrodes 130 can overlap or beadjacent to the second transparent electrodes 132 in the first or secondinterstitial areas 12, 14.

There are various methods of the present invention that can be employedto construct the various embodiments of the present invention. Referringto FIG. 5A, a method of making a transparent touch-responsive capacitorapparatus 10 includes providing a transparent substrate (e.g. 122, 123,126) and defining a plurality of first pad areas 128 and firstinterstitial areas 12 in a first micro-wire layer and defining aplurality of second pad areas 129 and second interstitial areas 14 in asecond micro-wire layer, pairs of first and second pad areas 128, 129defining corresponding touch-responsive capacitors, the first and secondmicro-wire layers supported by the transparent substrate in step 200.

In step 205, a plurality of electrically connected first pad micro-wires24 are formed in the first pad areas 128 in the first micro-wire layerand a plurality of electrically connected first interstitial micro-wires22 are formed in the first interstitial areas 12 in the first micro-wirelayer, the first pad micro-wires 24 electrically connected to the firstinterstitial micro-wires 22. A plurality of electrically connectedsecond pad micro-wires 24 are formed in the second pad areas 129 in thesecond micro-wire layer and a plurality of electrically connected secondinterstitial micro-wires 22 are formed in the second interstitial areas14 in the second micro-wire layer, the second pad micro-wires 24electrically connected to the second interstitial micro-wires 22. Theheight of at least a portion of the first interstitial micro-wires 22 isgreater than the height of at least a portion of the first padmicro-wires 24.

While the present invention in this embodiment is described in terms offirst or second pad areas 128, 129 or first or second interstitial areas12, 14, in other embodiments the areas are simply and generallyconsidered as first interstitial areas 12 and second pad areas 129,wherein one of the areas, for example the first area 12 or 14, includesmicro-wires 150 that have a height greater than micro-wires 150 in thesecond area, for example 128 or 129.

There are several different ways in which the micro-wires 150 can beformed according to various methods of the present invention. In oneembodiment, the pad micro-wires 24 in the first or second pad areas 128,129 are made at the same time and with the same processing step as theinterstitial micro-wires 22 in the first or second interstitial areas12, 14. In another embodiment, the pad micro-wires 24 in the first orsecond pad areas 128, 129 are made in a different processing step fromthe interstitial micro-wires 22 in the first or second interstitialareas 12, 14. In the latter case, referring to FIG. 5B, the padmicro-wires 24 in the first or second pad areas 128, 129 are made instep 210 separately from the interstitial micro-wires 22 in the first orsecond interstitial areas 12, 14 in step 215. Alternatively, referringto FIG. 5C, the pad micro-wires 24 in the first or second pad areas 128,129 are made at the same times as a portion or first layer of theinterstitial micro-wires 22 in the first or second interstitial areas12, 14 in step 220. In a separate step 225, micro-wire material can beadded to the material in the first or second interstitial areas 12, 14.

In other embodiments of the present invention, the different micro-wires150 can be made by depositing unpatterned layers of material and thendifferentially processing the layers to form the different micro-wirestructures. For example, a first layer of curable material can be coatedover the transparent substrate (e.g. 122, 123, 126), pattern-wise curedin a first pattern and then a second layer of curable material coatedover the transparent substrate (e.g. 122, 123, 126) and first patternedmaterial. The second layer of curable material is then pattern-wisecured in a second pattern different from the first pattern. Referring toFIG. 6A, a first layer of materials can be deposited on a transparentsubstrate (e.g. 122, 123, 126) in step 270 and then processed in step275. A second layer of materials can be deposited on a transparentsubstrate (e.g. 122, 123, 126) in step 280 and then processed in step285. A variety of processing methods can be used, for examplephoto-lithographic methods. For example, the materials can bedifferentially pattern-wise exposed. Referring to FIG. 6B, a first layerof materials can be deposited on a transparent substrate (e.g. 122, 123,126) in step 300, pattern-wise exposed in step 305, and then processedin step 310. A second layer of materials can be deposited on atransparent substrate in step 315, pattern-wise exposed with a differentpattern in step 320, and then processed in step 325.

In any of these cases, the pad micro-wires 24 in the first or second padareas 128, 129 can be made before or after the interstitial micro-wires22 in the first or second interstitial areas 12, 14 on any of thetransparent substrates (e.g. in FIG. 5B). A portion of the interstitialmicro-wires 22 in the first or second interstitial areas 12, 14 can bemade before or after the pad micro-wires 24 in the first or second padareas 128, 129 and first or second interstitial areas 12, 14 (e.g. FIG.5C).

Thus, in another embodiment of the present invention illustrated inFIGS. 6A and 6B, a method of making a transparent touch-responsivecapacitor apparatus 10 includes providing a first transparent substrate122; defining a plurality of first and second spaced-apart pad areas128, 129 over the first transparent substrate 122, pairs of first andsecond pad areas 128, 129 defining corresponding touch-responsivecapacitors, and defining a plurality of first interstitial areas 12spaced apart from the first pad areas 128 and a plurality of secondinterstitial areas 14 spaced apart from the second pad areas 129;forming a first material layer over the first transparent substrate 122;forming a second material layer over the first material layer; forming aplurality of electrically connected interstitial micro-wires 22 over thefirst transparent substrate 122 in the first and second materialslayers; forming a plurality of electrically connected pad micro-wires 24over the first transparent substrate 122 in the first material layer,the interstitial micro-wires 22 electrically connected to the padmicro-wires 24; and wherein the height of at least a portion of theinterstitial micro-wires 22 is greater than the height of at least aportion of the pad micro-wires 24.

In a further embodiment of the present invention, referring to FIG. 7A,first and second precursor layers of spectrally photo-sensitiveprecursor materials on the transparent substrate are formed in steps 230and 235. The first layer is sensitive to a first spectrum and the secondlayer is sensitive to a second spectrum different from the firstspectrum. In certain embodiments, however, the first and second layersare sensitive to light of a common wavelength. For example, the firstlayer is sensitive to ultraviolet and red light whereas the second layeris sensitive only to ultraviolet. The first and second layers are bothpart of the common plane in which the micro-wires 150 are located whenformed. The photo-sensitive pre-cursor materials in the firstinterstitial area 12 are pattern-wise exposed to first-spectrum lightand, optionally, to second-spectrum light in the first step 240 toexpose both the first and second precursor layers. The pattern definesthe plurality of electrically connected first micro-wires 152. Thephoto-sensitive precursor materials in the pad area are pattern-wiseexposed to second-spectrum light in the second step 245 to expose onlyone of the precursor layers. Any of the exposures can be done in anyorder or at the same time as other exposures. The pattern defines theplurality of electrically connected second micro-wires 154. Thephoto-sensitive precursor materials in both layers in the pad and thefirst interstitial areas 12 are processed in step 250 to form the one ormore electrically conductive micro-wires 150.

A variety of materials can be employed to form the first and secondpatterned layers, including resins that can be cured by cross-linkingwave-length-sensitive polymeric binders and silver halide materials thatare exposed to light. Processing can include both washing out residualuncured materials and curing or exposure steps.

In order to enhance the sensitivity of the first and second precursorlayers to the first and second spectra, in another embodiment of thepresent invention, the first layer includes a first spectrally-sensitiveradiation-absorbing material and the second layer includes a secondspectrally-sensitive radiation-absorbing material different from thefirst spectrally-sensitive radiation-absorbing material. For example,the spectrally-sensitive radiation-absorbing materials can be dyes thatpreferentially absorb radiation used to pattern-wise expose thematerials. Referring to FIG. 8, a first layer 401 of a first spectrallyphoto-sensitive precursor material and a second layer 402 of a seconddifferent spectrally photo-sensitive precursor material are coated on afirst transparent substrate 122. Light L1 of a first spectrum passesthrough the second layer 402 and selectively exposes the first layer 401with a first pattern, for example corresponding to the pattern of thepad micro-wires 24 in the first or second pad areas 128, 129 andcorresponding to the pattern of the interstitial micro-wires 22 in thefirst or second interstitial areas 12, 14. Light L2 of a second spectrumexposes at least the second layer 402 (and optionally the first layer401) and with a second pattern, for example corresponding to the patternof the interstitial micro-wires 22 in the first or second interstitialareas 12, 14. Thus, the photo-sensitive precursor material in the firstlayer 401 forms micro-wires 150 in the first or second pad 128, 129 andfirst or second interstitial areas 12, 14 while the photo-sensitiveprecursor material in the second layer 402 adds additional material tothe micro-wires 150 in the first or second interstitial areas 12, 14(for example as illustrated in FIGS. 5C and 7A). In a processing step,the exposed first and second layers can be developed (e.g. cross-linked)and unexposed materials removed to form the one or more micro-wires 150.

In an embodiment, the first and second precursor layers includeconductive inks, conductive particles, or metal ink. The exposedportions of the first and second layers are cured to form themicro-wires 150 (for example by exposure to patterned laser light tocross-link a curable resin) and the uncured portions removed.Alternatively, unexposed portions of the first and second layers arecured to form the micro-wires 150 and the cured portions removed.

In another embodiment of the present invention, the first and secondprecursor layers are silver salt layers. The silver salt can be anymaterial that is capable of providing a latent image (that is, a germ ornucleus of metal in each exposed grain of metal salt) according to adesired pattern upon photo-exposure. The latent image can then bedeveloped into a metal image.

For example, the silver salt can be a photosensitive silver salt such asa silver halide or mixture of silver halides. The silver halide can be,for example, silver chloride, silver bromide, silver chlorobromide, orsilver bromoiodide.

Generally, the silver salt layer includes one or more hydrophilicbinders or colloids. Non-limiting examples of such hydrophilic bindersor colloids include but are not limited to hydrophilic colloids such asgelatin or gelatin derivatives, polyvinyl alcohol (PVA),polyvinylpyrrolidone (PVP), casein, and mixtures thereof.

In many embodiments, the binder in the silver salt layer (or any otherlayer) includes one or more hardeners designed to harden the particularbinder such as gelatin. Particularly useful hardeners include, but arenot limited to, non-polymeric vinyl-sulfones such as bis(vinyl-sulfonyl)methane (BVSM), bis(vinyl-sulfonyl methyl)ether (BVSME), and1,2-bis(vinyl-sulfonyl acetoamide)ethane (BVSAE). Mixtures of hardenerscan be used if desired.

One useful photosensitive silver salt composition is a high metal (forexample, silver)/low binder (for example, gelatin) composition, thatafter silver salt development, is sufficiently conductive. Where thephotosensitive silver salt layer includes an emulsion of silver halidedispersed in gelatin, a particularly useful weight ratio of silver togelatin is 1.5:1 or higher in the silver salt layer. In certainembodiments, a ratio between 2:1 and 3:1 in the silver salt layer isparticularly useful.

According to many embodiments, the useful silver salt is a silver halide(AgX) that is sensitized to any suitable wavelength of exposingradiation. Organic sensitizing dyes can be used to sensitize the silversalt to visible or IR radiation, but it can be advantageous to sensitizethe silver salt in the UV portion of the electromagnetic spectrumwithout using sensitizing dyes.

Processing of AgX materials to form conductive traces typically involvesat least developing exposed AgX and fixing (removing) unexposed AgX.Other steps can be employed to enhance conductivity, such as thermaltreatments, electroless plating, physical development and variousconductivity enhancing baths, e.g., as described in U.S. Pat. No.3,223,525.

In an embodiment, a method of making a transparent conductor structureuseful for touch screen and other electronic devices includes providinga transparent conductor precursor structure. The transparent conductorprecursor structure includes a transparent substrate (e.g. 122, 123,126), a first precursor material layer formed over the transparentsubstrate (e.g. 122, 123, 126) and a second precursor material layerformed on the first precursor material layer. A plurality ofelectrically connected first micro-wires 152 is formed in the first andsecond precursor material layers within a first transparent conductorarea. That is, the conductive first micro-wire 152 spans at least aportion of both the first and second precursor material layers.

A plurality of electrically connected second micro-wires 154 are formedin either the first precursor material layer or the second precursormaterial layer within a second transparent conductor area, the secondmicro-wires 154 electrically connected to the first micro-wires 152.When the second micro-wires 154 are formed in the first precursormaterial layer, some portion of a second micro-wire 154 can be formed inthe second precursor material layer as well, but in a lesser amount thanin the first precursor material layer. In a useful embodiment,substantially no portion of the second micro-wire 154 is formed in thesecond precursor material layer. Similarly, when the second micro-wires154 are formed in the second precursor material layer, some smallerportion of a second micro-wire 154 can be formed in the first precursormaterial layer. It can be particularly useful if there is substantiallyno portion of the second micro-wire 154 formed in the first precursormaterial layer.

The height of at least a portion of the first micro-wires 152 is greaterthan the height of at least a portion of the second micro-wires 154 andto achieve transparency, the total area occupied by the firstmicro-wires 152 is less than 15% of the first transparent conductor areaand the total area occupied by the second micro-wires 154 is less than15% of the second transparent conductor area. The transparent conductivestructure can include a plurality of first and second transparentconductor areas.

As in embodiments described above, the first precursor material layercan be photosensitive to a first-spectrum light and the second precursormaterial layer is photosensitive to a second-spectrum light differentfrom the first spectrum light. In some embodiments, the first precursormaterial layer is also photosensitive to the second-spectrum light andthe second precursor material layer is substantially insensitive tofirst-spectrum light.

In an embodiment, the transparent precursor material layer ispattern-wise exposed in the first transparent conductor area tosecond-spectrum light, and optionally to first-spectrum light, definingthe plurality of electrically connected first micro-wires 152. Thetransparent precursor material layer is also pattern-wise exposed in thesecond transparent conductor area to first-spectrum light defining theplurality of electrically connected second micro-wires 154. Afterexposure, the precursor material layer is processed to form the firstand second micro-wires 152, 154. In a particularly useful embodiment,the first and second precursor material layers each include aphotosensitive precursor material, e.g., silver halide, provided in abinder material, such as gelatin.

In an embodiment, the transparent precursor material layer ispattern-wise exposed in the first transparent conductor area tofirst-spectrum light and second-spectrum light, defining the pluralityof electrically connected first micro-wires 152. The transparentprecursor material layer is pattern-wise exposed in the secondtransparent conductor area to first- or second-spectrum light definingthe plurality of electrically connected second micro-wires 154. Ifformation of the second micro-wires 154 is desired primarily in thefirst precursor material layer, first-spectrum light is used.Alternatively, if formation of the second micro-wires 154 is desiredprimarily in the second precursor material layer, second-spectrum lightis used. After exposure, the transparent precursor material layer isprocessed to form the first and second micro-wires 152, 154. In aparticularly useful embodiment, the first and second precursor materiallayers each include a photosensitive precursor material, e.g., silverhalide, provided in a binder material, such as gelatin.

In an embodiment, the first and second precursor material layers caneach include a metallic particulate material or a metallic precursormaterial, and a photosensitive binder material.

As noted above with reference to FIG. 5B, in an embodiment the one ormore pad micro-wires 24 in the first (or second) pad areas 128 (129) areformed in the first step and the one or more interstitial micro-wires 22in the first or second interstitial areas 12, 14 are formed in thesecond step. For example, referring to FIG. 7B, first precursor materialis deposited in the first (or second) pad areas 128 (129) in step 260and pattern-wise processed in step 265. Second precursor material isdeposited in the first (or second) interstitial area 12 (14) andpattern-wise processed. The first and second precursor materials can beliquid (for example a conductive, curable ink) and can be blanket coatedin one step and pattern-wise cured by pattern-wise exposing the blanketcoating in the first or second pad 128, 129 and first or secondinterstitial areas 12, 14. In the second step, the first transparentsubstrate 122 is blanket coated a second time and pattern-wise cured inonly the first or second interstitial areas 12, 14 (corresponding to theprocess illustrated in FIG. 5C).

In an alternative embodiment, first precursor material is pattern-wisedeposited and cured in the first (or second) pad areas 128, (129) andsecond precursor material is pattern-wise deposited and cured in thefirst (or second) interstitial area 12 (14) (e.g. corresponding to theprocess illustrated in FIG. 5B). Thus, the one or more pad micro-wires24 are formed in the first (or second) pad areas 128 (129) and a portionof each of the one or more interstitial micro-wires 22 in the first (orsecond) interstitial areas 12 (14) in a first step and the remainder ofthe one or more interstitial micro-wires 22 in the first (or second)interstitial areas 12 (14) is formed in a second step after the firststep. The first precursor material is deposited in the first (or second)pad areas 128 (129) and the first (or second) interstitial areas 12 (14)and pattern-wise processed and second precursor material is deposited inthe first (or second) interstitial areas 12 (14) and pattern-wiseprocessed to form the interstitial micro-wires 22. The deposition caninclude blanket-coating the transparent substrate and pattern-wiseexposing the blanket coating. Blanket coating methods are known in theart, for example by spin coating or curtain coating.

In another embodiment, the deposition and curing are different in thesecond step to provide interstitial micro-wires 22 having a greaterheight in the first or second interstitial areas 12, 14 compared to thepad micro-wires 24 in the first (or second) pad areas 128 (129).Different materials can be used in the second step than in the firststep.

In yet another embodiment, first precursor material can be pattern-wisedeposited in the first (or second) pad areas 128 (129) and the first (orsecond) interstitial areas 12 (14). Second precursor material ispattern-wise deposited in the first (or second) interstitial areas 12(14). The first precursor material can be pattern-wise deposited beforethe second precursor material or the second precursor material can bepattern-wise deposited before the first precursor material. Thedeposited materials can be processed or cured after each deposition orthe deposited materials can be processed or cured at one time after theyhave been pattern-wise deposited. Pattern-wise deposition methods areknown in the art, for example by inkjet printing, as are curableprecursor materials, for example silver inks.

In another embodiment of the present invention, the steps include thepattern-wise transfer of precursor material from a source to thetransparent substrate.

In another embodiment of the present invention, precursor materials aredeposited in a layer, for example in a step, and then pattern-wisedefined in one or more steps. In such a method, a transparent substrate(e.g. 122, 123, 126) is provided. A plurality of first and secondspaced-apart first and second pad areas 128, 129 is defined over thefirst transparent substrate 122, pairs of first and second pad areas128, 129 defining corresponding touch-responsive capacitors. A pluralityof first interstitial areas 12 spaced apart from the first pad areas 128and a plurality of second interstitial areas 14 spaced apart from thesecond pad areas 129 are defined. A precursor material layer is formedover the first transparent substrate 122. A plurality of electricallyconnected interstitial micro-wires 22 is pattern-wise defined over thefirst transparent substrate 122 in the material layer in the firstinterstitial areas 12. A plurality of electrically connected padmicro-wires 24 is pattern-wise defined over the first transparentsubstrate 122 in the material layer in the first pad areas 128. Theinterstitial micro-wires 22 are electrically connected to the padmicro-wires 24 in the same micro-wire layer. The height of at least aportion of the interstitial micro-wires 22 is greater than the height ofat least a portion of the pad micro-wires 24.

Referring to FIG. 9, in an embodiment of the present invention, aprinting plate 405 is provided. The printing plate has first and secondflexible raised areas 410, 415, the first raised areas 410 having adifferent height H3 above the printing plate 405 than the height H4 ofthe second raised areas 415. A flexible raised area is one which can becompressed when brought into contact with a rigid surface. A material420 is deposited on each of the first and second raised areas 410, 415on the printing plate 405. A first transparent substrate 122 is locatedin contact with the first and second raised areas 410, 415 todifferentially transfer different amounts of material 420 from the firstraised and second raised areas 410, 415 on to the first transparentsubstrate 122. Because the first and second raised areas 410, 415 areflexible, the higher raised area is compressed by the first transparentsubstrate 122 so that the first transparent substrate 122 surface isbrought into contact with the material 420 on both of the first andsecond raised areas 410, 415. The material 420 is then transferred fromthe first raised areas 410 to define the plurality of electricallyconnected first micro-wires 152 and the material 420 is transferred fromthe second raised areas 415 to define the plurality of electricallyconnected second micro-wires 154. The transferred material 420 is thenprocessed as needed to form the first and second micro-wires 152, 154.The amount of material 420 transferred from the first and second raisedareas 410, 415 to the first transparent substrate 122 depends on avariety of factors, including the viscosity of the material 420, therelative height of the raised areas, the distance the first raised area410 is apart from the second raised area 415, and the temperatures ofthe material 420, the first and second raised areas 410, 415, or thefirst transparent substrate 122. Flexographic printing plates havingflexible raised areas are known in the art.

In a further embodiment of the present invention, a photo-sensitiveprecursor material 420 is coated on the transparent substrate (e.g. 122,123, 126) and pattern-wise first exposed in the first interstitial area12 to define the plurality of electrically connected first micro-wires152. The photo-sensitive precursor material in the pad area ispattern-wise second exposed to define the plurality of electricallyconnected second micro-wires 154. The second exposure is different fromthe first exposure. The photo-sensitive precursor material 420 isprocessed in both the first pad area 128 and the interstitial areas 12to form the one or more electrically conductive micro-wires 150.

In various embodiments, the photo-sensitive precursor material 420 isresponsive to two different spectral wavelengths, the first exposure isdone at the same time as the second exposure, or the first exposure isdone at a different time than the second exposure. The second exposurecan be longer, hotter, or of a different frequency than the firstexposure.

In any of these cases, the precursor material 420 is electricallyconductive after it is cured and any needed processing completed. Beforepatterning or before curing, the precursor material 420 is notnecessarily electrically conductive. As used herein, precursor material420 is material that is electrically conductive after any finalprocessing is completed and the precursor material 420 is notnecessarily conductive at any other point in the micro-wire formationprocess.

Referring to FIG. 14 in a further embodiment of the present invention,an electronic device 8 includes a support 30 having greater than 80%transmittance to light at 550 nm and a transparent conductor area 40provided over at least a portion of one side of the support 30. Thesupport 30 can be a transparent substrate, for example similar totransparent substrate 122, 126, or 123 (FIG. 1A, 4B). The transparentconductor area can be, for example a transparent electrode such as firsttransparent electrodes 130 or second transparent electrodes 132 (FIG.1A, 2A, 2B).

Referring also to FIG. 15, the transparent conductor area 40 includesfirst conductive metallic micro-wires 152 provided in first locations 26in a first micro-pattern, the first conductive metallic micro-wires 152having a width in a range from 0.5 um to 20 um and a first height H1.Second conductive metallic micro-wires 154 are provided in secondlocations 28 different from the first locations 26 in a secondmicro-pattern. The second conductive metallic micro-wires 154 have asecond height H2 that is less than the first height H1 and a width in arange from 0.5 um to 20 um. The first and second metallic micro-wires152, 154 can correspond to the interstitial micro-wires 22 and the padmicro-wires 24, respectively.

The first and second metallic micro-wires 152, 154 occupy an area lessthan 15% of the transparent conductor area 40.

Referring to FIG. 16 in an embodiment of the present invention, thetransparent conductor layer 40 includes at least first and second layers51, 52. The first metallic micro-wires 152 (not shown in FIG. 16) areformed in the first layer 51 and the second metallic micro-wires 154(not shown in FIG. 16) are formed in both the first and second layers51, 52. In a further embodiment, the first metallic micro-wires 152 havea metallic bi-layer structure, for example including a first layer 51and a second layer 52 formed on the support 30, as illustrated in FIG.16. In an embodiment, the first layer 51 is closer to the support 30than the second layer 52. Alternatively, the second layer 52 is closerto the support 30 than the first layer 51. In another embodiment, thefirst and second layers 51, 52 include binder, for example gelatin, andthe first and second metallic micro-wires 152, 154 include silver. Thefirst and second metallic micro-wires 152, 154 can be constructed usingthe methods described above for the pad micro-wires 24 and interstitialmicro-wires 22 for the first and second transparent electrodes 130, 132.

As shown in FIG. 14, the electronic device 8 further can include aplurality of transparent conductor areas 40, each forming a transparentelectrode (e.g. 130, 132) having a length and a width. In one embodimentas shown in FIG. 2A, the width of the first and second transparentelectrodes 130, 132 varies along the length of the first and secondtransparent electrodes 130, 132 to form wide and narrow transparentelectrode areas. The first metallic micro-wires 152 are provided in widetransparent electrode areas (for example the first and second pad areas128, 129) and the second metallic micro-wires 154 are provided in thenarrow transparent electrode areas (for example the first and secondinterstitial areas 12, 14).

In one embodiment, the first micro-pattern is the same as the secondmicro-pattern (e.g. as shown in FIG. 3). In another embodiment, thefirst micro-pattern is different from the second micro-pattern (e.g. asshown in FIGS. 14 and 15). In a further embodiment as illustrated inFIGS. 15 and 16, the second height H2 is at least 30% less than thefirst height H1.

The second micro-wires 154 can have a greater conductivity than thefirst micro-wires 152. The second micro-wires 154 can be made of thesame, or different, materials as the first micro-wires 152. The metallicfirst and second micro-wires 152, 154 can occupy an area less than orequal to 10% of the area of the transparent conductor area 40. Thetransparent conductor area 40 can have a transparency greater than 80%transmittance to light at 550 nm and the combined transparency of thesupport 30 and the transparent conductor area 40 is greater than 80% ina wavelength range of 450 to 650 nm.

It is known in the art that some touch screen designs using micro-wires150 can optionally include “dummy areas” outside the conductive areaswhere conductive micro-wires 150 are formed, but are not electricallyconnected to any addressable electrode, for primarily optical purposes.Although the conductive areas can be transparent, they can have slightlymore light absorption than neighboring non-conductive areas. This cansometimes be observed by a viewer. Thus, in order to maintain a uniformappearance, dummy areas include some micro-wire patterns to maintain asimilar overall light absorption. In the embodiments above, when dummyareas are desired, it is preferred to use micro-wires 150 that have asmaller height than the height of the interstitial micro-wires 22 orfirst micro-wires 152 since the dummy area micro-wires 150 do not needto conduct electricity and can therefore have a lower conductivitywithout deleteriously affecting the performance of the touch screen. Forexample, the dummy area micro-wires 150 can have a height comparable topad micro-wires or second micro-wires 154. In another embodiment, thedummy area micro-wires 150 have a height smaller than any of thetransparent conductive area micro-wires 150.

Therefore, referring to FIGS. 17 and 18, in one embodiment of thepresent invention, a transparent conductor apparatus 11 includes a firsttransparent substrate 122, a plurality of electrically connected firstmicro-wires 152 formed in a plurality of first interstitial areas 12 ina micro-wire layer, a plurality of electrically connected secondmicro-wires 154 formed in a plurality of second areas 128 in themicro-wire layer, the first micro-wires 152 electrically connected tothe second micro-wires 154, and a plurality of third micro-wires 158formed in a plurality of third areas (e.g. dummy area 160) in themicro-wire layer, the third micro-wires 158 electrically disconnectedfrom the first micro-wires 152 and the second micro-wires 154. The firsttransparent substrate 122 supports the micro-wire layer and the heightof at least a portion of the first or second micro-wires 152, 154 isgreater than the height of at least a portion of the third micro-wires158. The first interstitial areas 12 can correspond to first or secondinterstitial areas 12, 14, the second areas can correspond to pad areas128, 129, and the third areas can correspond to dummy areas 160.

In various embodiments, the height of at least a portion of the firstmicro-wires 152 and second micro-wires 154 is greater than the height ofat least a portion of the third micro-wires 158. Alternatively, theheight of at least a portion of the first micro-wires 152, the secondmicro-wires 154, and the third micro-wires 158 are different. Forexample, the height of at least a portion of the first micro-wires 152is greater than at least a portion of the second micro-wires 154 and atleast a portion of the second micro-wires 154 is greater than at least aportion of the third micro-wires 158.

In an embodiment, the width of the third micro-wires 158 is the same asthe width of the first micro-wires 152 or the second micro-wires 154. Bymaking the width or micro-pattern of the micro-wires 150 in thedifferent areas the same, optical uniformity is enhanced. Thus, in afurther embodiment, the third micro-wires 158 form a micro-pattern thatis the same as a micro-pattern formed by the first micro-wires 152 or isthe same as a micro-pattern formed by the second micro-wires 154.

To enable efficient manufacturing and further improve opticaluniformity, in an embodiment the third micro-wires 158 and the first orsecond micro-wires 152, 154 are made of the same material. Usefulmaterials include a metal, a metal alloy, or include cured or sinteredmetal particles. Such metals can be nickel, tungsten, silver, gold,titanium, or tin or include nickel, tungsten, silver, gold, titanium, ortin.

In a further embodiment of the present invention, a transparentsubstrate (e.g. 122, 123, 126) is a support having greater than 80%transmittance to light at 550 nm and further includes a transparentconductor area having the first, second, and third micro-wires 152, 154,158. The first second, and third micro-wires 152, 154, 158 each have awidth in a range from 0.5 um to 20 um and occupy an area less than 15%of the transparent conductor area. Such an arrangement improves thetransparency of the transparent conductor apparatus 11.

In another embodiment of the present invention and referring to FIGS.1A, 1B 2A, 2B, 3, 17, and 18, a touch-responsive capacitive apparatus 10includes a first transparent substrate 122. A plurality of electricallyconnected first pad micro-wires 24 are formed in a plurality of firstpad areas 128 in a first micro-wire layer and a plurality ofelectrically connected first interstitial micro-wires 22 are formed in aplurality of first interstitial areas 12 in the first micro-wire layer,the first pad micro-wires 24 electrically connected to the interstitialmicro-wires 22. A plurality of electrically connected second padmicro-wires 24 are formed in a plurality of second pad areas 129 in asecond micro-wire layer and a plurality of electrically connected secondinterstitial micro-wires 22 are formed in a plurality of secondinterstitial areas 14 in the second micro-wire layer, the second padmicro-wires 24 electrically connected to the second interstitialmicro-wires 22. A plurality of first dummy micro-wires 23 are formed ina plurality of dummy areas 160 in the first micro-wire layer, the dummymicro-wires electrically disconnected from the first interstitialmicro-wires 22 and from first pad micro-wires 24. Pairs of first andsecond pad areas 128, 129 define corresponding touch-responsivecapacitors, the first transparent substrate 122 supports the first orsecond micro-wire layers and the height of at least a portion of thefirst interstitial micro-wires 22 or first pad micro-wires 24 is greaterthan the height of at least a portion of the first dummy micro-wires 23.Dummy areas 160 are discussed in the above-referenced U.S. PatentPublication 2011/0289771.

In a further embodiment, a plurality of dummy micro-wires 23 are formedin a plurality of dummy areas 160 in the second micro-wire layer, thedummy micro-wires 23 electrically disconnected from the interstitialmicro-wires 22 in the second micro-wire layer or from the padmicro-wires 24 in the second micro-wire layer. The height of at least aportion of the interstitial micro-wires or pad micro-wires 22, 24 isgreater than the height of at least a portion of the dummy micro-wires23.

Referring to FIG. 20A, a first transparent substrate 122 has aninterstitial micro-wire 22 and a dummy micro-wire 23 formed thereon, theinterstitial micro-wire 22 having a greater height than the dummymicro-wire 23. This corresponds to a cross section having a firstinterstitial area 12 and dummy area 160. Referring to FIG. 20B, a firsttransparent substrate 122 has a pad micro-wire 24 and a dummy micro-wire23 formed thereon, the pad micro-wire 24 also having a greater heightthan the dummy micro-wire 23. This corresponds to a cross section havinga first interstitial area 12 and dummy area 160. In comparing FIGS. 20Aand 20B, the interstitial micro-wire 22 has a height greater than theheight of the pad micro-wire 24 (as is also shown in FIGS. 4A and 4B).

In an embodiment, for example that of FIG. 18, and also referring toFIGS. 19A and 19B, the first dummy areas 162 overlap the second dummyareas 164 so that the dummy micro-wires 23 are offset. In anotherembodiment (not shown), the first dummy areas 162 are adjacent to thesecond dummy areas 164.

Referring to FIG. 18, the dummy micro-wires 23 are aligned in theoverlapping dummy areas 160 so that, in a top view, only the micro-wires150 in the first micro-wire layer can be seen. The micro-wires 150 (notshown) in the first micro-layer obscure the micro-wires 150 in thesecond micro-layer. In another embodiment illustrated in FIG. 19C, thefirst dummy micro-wires 23 in the first micro-wire layer are offset withrespect to the second dummy micro-wires 23 in the second micro-layer. Inother embodiments, only the first or the second dummy areas 160 hasmicro-wires 23.

In one arrangement useful in an embodiment of the present invention andillustrated in FIG. 18, the first interstitial area 12, the first padarea 128, the second interstitial area 14 and the first dummy area 160are four quadrants of a rectangular area.

In a further embodiment of the present invention, a transparentsubstrate (e.g. 122, 123, 126) is a support 30 having greater than 80%transmittance to light at 550 nm. A transparent conductor area 40 hasinterstitial micro-wires 22, pad micro-wires 24, and dummy micro-wires23. The interstitial micro-wires 22, pad micro-wires 24, and dummymicro-wires 23 each have a width in a range from 0.5 um to 20 um andoccupy an area less than 15% of the transparent conductor area 40.

In another embodiment, the transparent conductors are connected to buslines having a width significantly greater than the micro-wires. Buslines are often outside of an intended viewing area. Nevertheless, thebus lines can be formed in a manner similar to the interstitialmicro-wires 22 or first micro-wires 152 so that their height is greaterthan the height of the pad micro-wires 24 or interstitial micro-wires22. This can reduce resistivity of bus lines.

Although the present invention has been described with emphasis oncapacitive touch screen embodiments, the transparent electrodestructures are useful in a wide variety of electronic devices. Suchdevices can include, for example, photovoltaic devices, OLED displaysand lighting, LCD displays, plasma displays, inorganic LED displays andlighting, electrophoretic displays, electrowetting displays, dimmingmirrors, smart windows, transparent radio antennae, transparent heatersand other touch screen devices such as resistive touch screen devices.

The invention has been described in detail with particular reference tocertain embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

PARTS LIST

-   A cross-section line-   H1 height 1-   H2 height 2-   H3 height 3-   H4 height 4-   L1 light of spectrum one-   L2 light of spectrum two-   8 electronic device-   10 touch-responsive capacitor apparatus-   11 transparent conductor apparatus-   12 first interstitial area, first area-   14 second interstitial area, first area-   22 interstitial micro-wires, tall micro-wire-   23 dummy micro-wires-   24 pad micro-wires, short micro-wire-   26 first locations-   28 second locations-   30 support-   40 transparent conductor area-   51 first layer-   52 second layer-   100 touch screen and display system-   110 display-   120 touch screen-   122 first transparent substrate-   123 transparent substrate-   123A first side-   123B second side-   124 dielectric layer-   126 second transparent substrate-   128 first pad area, second area-   129 second pad area, second area-   130 x-dimension first transparent electrodes-   132 y-dimension second transparent electrodes-   134 electrical buss connections-   136 electrical buss connections-   140 touch screen controller-   142 display controller-   150 micro-wires-   152 first micro-wires-   154 second micro-wires-   156 micro-pattern-   158 third micro-wires-   160 dummy area-   162 first dummy area-   164 second dummy area-   200 provide transparent substrate step-   205 form micro-wires step-   210 form micro-wires in pad areas step-   215 form micro-wires in interstitial areas step-   220 form micro-wires in pad and interstitial areas step-   225 add micro-wire material in interstitial areas step-   230 form spectrally-sensitive first layer step-   235 form spectrally-sensitive second layer step-   240 expose first layer step-   245 expose second layer step-   250 process first and second layers step-   260 pattern-wise deposit liquid materials step-   265 process patterned liquid materials step-   270 deposit layer 1 materials step-   275 process layer 1 materials step-   280 deposit layer 2 materials step-   285 process layer 2 materials step-   300 deposit layer 1 materials step-   305 pattern-wise expose layer 1 materials step-   310 process layer 1 materials step-   315 deposit layer 2 materials step-   320 pattern-wise expose layer 2 materials step-   325 process layer 2 materials step-   401 first layer-   402 second layer-   405 printing plate-   410 first raised area-   415 second raised area-   420 material

1. A touch-responsive capacitive apparatus, comprising: a transparentsubstrate; a plurality of electrically connected first pad micro-wiresformed in a plurality of first pad areas in a first micro-wire layer anda plurality of electrically connected first interstitial micro-wiresformed in a plurality of first interstitial areas in the firstmicro-wire layer, the first pad micro-wires electrically connected tothe first interstitial micro-wires; a plurality of electricallyconnected second pad micro-wires formed in a plurality of second padareas in a second micro-wire layer and a plurality of electricallyconnected second interstitial micro-wires formed in a plurality ofsecond interstitial areas in the second micro-wire layer, the second padmicro-wires electrically connected to the second interstitialmicro-wires; and wherein pairs of first and second pad areas definecorresponding touch-responsive capacitors, the transparent substratesupports the first or second micro-wire layers, and the height of atleast a portion of the first interstitial micro-wires is greater thanthe height of at least a portion of the first pad micro-wires.
 2. Thetouch-responsive capacitive apparatus according to claim 1, wherein thewidth of the first interstitial micro-wires is the same as the width ofthe first pad micro-wires.
 3. The touch-responsive capacitive apparatusaccording to claim 1, wherein one or more first pad micro-wires in afirst pad area is electrically connected to one or more first padmicro-wires in a different first pad area by one or more firstinterstitial micro-wires.
 4. The touch-responsive capacitive apparatusaccording to claim 1, further including a dielectric layer having afirst side adjacent the first micro-wire layer and a second sideopposite the first side adjacent the second micro-wire layer.
 5. Thetouch-responsive capacitive apparatus according to claim 4, wherein thetransparent substrate provides the dielectric layer or the dielectriclayer is separate from the transparent substrate.
 6. Thetouch-responsive capacitive apparatus according to claim 1, wherein theheight of at least a portion of the second interstitial micro-wires isgreater than the height of at least a portion of the second padmicro-wires.
 7. The touch-responsive capacitive apparatus according toclaim 1, wherein the transparent substrate has a surface and a first padarea is adjacent to a second pad area in a direction parallel to thesurface.
 8. The touch-responsive capacitive apparatus according to claim1, wherein the transparent substrate has a surface and a first pad areais adjacent to a second pad area in a direction orthogonal to thesurface.
 9. The touch-responsive capacitive apparatus according to claim1, wherein the first micro-wire layer is formed on a first transparentsubstrate and the second micro-wire layer is formed on a secondtransparent substrate different from the first transparent substrate.10. The touch-responsive capacitive apparatus according to claim 1,wherein the transparent substrate has a first side and a second sideopposed to the first side, and wherein the first micro-wire layer isformed on the first side and the second micro-wire layer is formed onthe second side.
 11. The touch-responsive capacitive apparatus accordingto claim 1, wherein the width of the second interstitial micro-wires isthe same as the width of the second pad micro-wires.
 12. Thetouch-responsive capacitive apparatus according to claim 1, wherein thefirst or second pad or interstitial micro-wires are a metal, a metalalloy, or include cured or sintered metal particles.
 13. Thetouch-responsive capacitive apparatus according to claim 12, wherein themetal is nickel, tungsten, silver, gold, titanium, or tin or includesnickel, tungsten, silver, gold, titanium, or tin.
 14. Touch-responsivecapacitor apparatus, comprising: a transparent substrate having firstand second sides; a plurality of first pad micro-wires formed in aplurality of spaced-apart first pad areas in a first micro-wire layerover or on the first side and a plurality of first interstitialmicro-wires formed in a plurality of spaced-apart first interstitialareas spaced apart from the first pad areas in the first micro-wirelayer, the first interstitial micro-wires electrically connected to thefirst pad micro-wires; a plurality of second pad micro-wires formed in aplurality of spaced-apart second pad areas in a second micro-wire layerunder or on the second side and a plurality of second interstitialmicro-wires formed in a plurality of spaced-apart second interstitialareas in the second micro-wire layer, the second interstitialmicro-wires electrically connected to the second pad micro-wires; adielectric layer located between the first and second micro-wire layers;and wherein the first and second pad areas define correspondingtouch-responsive capacitors whose capacitance changes in response to atouch, and the height of at least a portion of the first interstitialmicro-wires is greater than the height of at least a portion of thefirst pad micro-wires or the height of at least a portion of the secondpad micro-wires is greater than the height of at least a portion of thesecond interstitial micro-wires.
 15. The touch-responsive capacitorapparatus according to claim 15, wherein the transparent substrateprovides the dielectric layer or the dielectric layer is separate fromthe transparent substrate.
 16. A method of making a transparenttouch-responsive capacitor apparatus, comprising: providing atransparent substrate; forming a plurality of electrically connectedfirst pad micro-wires in a plurality of first pad areas in a firstmicro-wire layer and forming a plurality of electrically connected firstinterstitial micro-wires in a plurality of first interstitial areas inthe first micro-wire layer, the first pad micro-wires electricallyconnected to the first interstitial micro-wires; forming a plurality ofelectrically connected second pad micro-wires in a plurality of secondpad areas in a second micro-wire layer and forming a plurality ofelectrically connected second interstitial micro-wires in a plurality ofsecond interstitial areas in the second micro-wire layer, the second padmicro-wires electrically connected to the second interstitialmicro-wires; and wherein pairs of first and second pad areas definecorresponding touch-responsive capacitors, the transparent substratesupports the first and second micro-wire layers, and the height of atleast a portion of the first interstitial micro-wires is greater thanthe height of at least a portion of the first pad micro-wires.
 17. Amethod of making a transparent touch-responsive capacitor apparatus,comprising: providing a transparent substrate having a first side and asecond side opposing the first side; forming a plurality of first padmicro-wires in a plurality of spaced-apart first pad areas in a firstmicro-wire layer over or on the first side and forming a plurality offirst interstitial micro-wires in a plurality of spaced-apart firstinterstitial areas spaced-apart from the first pad areas in the firstmicro-wire layer, the first interstitial micro-wires electricallyconnected to the first pad micro-wires; forming a plurality of secondpad micro-wires in a plurality of spaced-apart second pad areas in asecond micro-wire layer and forming a plurality of second interstitialmicro-wires in a plurality of spaced-apart second interstitial areasspaced-apart from the second pad areas in a second micro-wire layerunder or on the second side, the second interstitial micro-wireselectrically connected to the second pad micro-wires; locating adielectric layer between the first and second micro-wire layers; andwherein the height of at least a portion of the first interstitialmicro-wires is greater than the height of at least a portion of thefirst pad micro-wires or the height of at least a portion of the secondpad micro-wires is greater than the height of at least a portion of thesecond interstitial micro-wires.
 18. The method according to claim 17,wherein the first pad micro-wires are made at the same time and with thesame processing step as the first interstitial micro-wires.
 19. Themethod according to claim 17, wherein the first pad micro-wires are madein a different processing step than the first interstitial micro-wires.20. The method according to claim 1, wherein the first pad micro-wiresare made of a different material than the first interstitialmicro-wires.
 21. The method of claim 1, wherein one or more of the firstinterstitial micro-wires has a different height from one or more otherfirst interstitial micro-wires.